单项选择题 In order to allow the establishment of a Telnet session with a router, which set of commands must be configured?（）

单项选择题 Whiletroubleshootinganetworkconnectivityproblem,atechnicianobservessteadylinklightsonboththeworkstationNICandtheswitchporttowhichtheworkstationisconnected.However,whenthepingcommandisissuedfromtheworkstation,theoutputmessage"Requesttimedout."isdisplayed.AtwhichlayeroftheOSImodeldoestheproblemmostlikelyexist?（）

多项选择题 WhichtwovaluesareusedbySpanningTreeProtocoltoelectarootbridge?(Choosetwo.)（）。